1. Field of the Invention
This invention pertains to welding machines, and more particularly to the protection of welding machine controls.
2. Description of the Prior Art
Self-contained welding machines are well known. Such machines include a frame to which a prime mover and a generator are mounted. The generator produces electrical power that is converted by various electro-magnetic devices into power suitable for welding purposes. The welding power is typically available at a pair of terminals on the machine. The generator and electro-magnetic devices are covered by a protective enclosure.
To operate the welding machine, that is, to make the proper welding power available at the terminals, the welding machine is equipped with several controls in the form of selector switches, rheostats, polarity switches, and similar components. The controls are typically mounted on the inside of a control panel that forms part of the protective enclosure. Hand knobs and handles located on the outside of the control panel connect to the various controls and enable a person to operate the machine.
Self-contained welding machines are frequently used in adverse conditions, so they must be ruggedly built. It is particularly important that the machine control knobs be protected from accidental bumping that might damage them or upset the machine operation. In many prior machines, the control panel formed an outermost plane of the protective enclosure. Consequently, the control knobs protruded into space outside of the protective enclosure. At such locations, the knobs were prone to being damaged. Further, the prior protective enclosure, including the control panel, did not present a particularly attractive appearance.
Static welding machines, i.e., welding machines that obtain their electrical power from a central source, are usually smaller and less ruggedly built than self-contained welding machines. In addition, the welding gun cables of static welding machines are dedicated to the machine so the operator need not attach the cables to nor remove them from the machine. Consequently, the safety factor associated with the cables is less acute than with self-contained welding machines. In some prior static machines, the control panel is recessed.
It is considered desirable to incorporate some of the features of static welding machines into self-contained welding machines while at the same time improving the safety of self-contained welding machines.